Bio-inspired textiles recover oil from water

By Gerald Ondrey | March 1, 2020

A technology that removes oil from the surface of water without pumps or chemicals has been developed by German researchers at the Universities of Bonn (www.uni-bonn.de) and Aachen (www.uni-aachen.de) and textile-manufacturer Heimbach GmbH (Düren, Germany; www.heimbach.com). Textiles with special surface properties passively skim off the oil and move it into a floating container. The study has now been published in the journal Philosophical Transactions A.
The textile surfaces are modeled after the floating fern Salvinia: its leaves are superhydrophobic, so when submerged they wrap themselves in an air jacket and remain completely dry. At the same time, the Salvinia surface is superoleophilic. “This allows the leaves to transport an oil film on their surface [photos],” explains Wilhelm Barthlott, professor emeritus of the University of Bonn and former director of its botanic gardens. “And we have also been able to transfer this property to technically producible surfaces, such as textiles.”
Unlike other materials that have been used for soaking up oil spills, these “bionic oil adsorbers” (BOAs) do not absorb the oil. “Instead, it travels along the surface of the fabric, moved forward solely by its adhesive forces,”…